Apparatus for manufacturing iron and steel



July 9, 1929. P. J. PEYRACHON APPARATUS FOR MANUFACTURING IRON AND STEELFiled May 2, 1927 2 Sheets-Sheet l INVENTOR;

PPS- Eiuvvrd Attorney.

y 9, 1929- P. J. PEYRACHON 1.720.055

APPARATUS FOR MANUFACTURING IRON AND STEEL File May 1927 2 Sheets-Sheet2 Flare 3585M! Peyrachon INVENTOR:

y WXA Attornoy Patented July 9, 1929.

UNITED STATES PATENT OFFICE.

PIERRE JOSEPH PEYBACHON, F LAI'ELGUERA, SPAIN.

APPARATUS FOR MANUFACTURING IRON AND STEEL.

Application fled Kay 8, 1827, Serial No. 188,085, and 1n I'ranaev July18, 1928.

One of the chief disadvantages which has,

up to the present time, prevented rotary furnaces from being extensivelyused in the modern manufacturing of iron is the great wear 5 and tear onthe lining of the lower section of the furnace, due to the hightemperature to which this part of the apparatus is subjected and to theprecarious cooling mea'ns employed. The use of pulverized carbon in themanufacture of open hearth steel, such as in the Siemens-Martin process,has .likewise not come into extensive use because of the rapid fillingup of the regenerating, chambers by the fine dust raised by the cinderof thepulverized carbon.

The object of this invention is, in general, to overcome thedisadvantages above enumeratcd.

To this end I provide the lining of my rotary furnace with a protectingscreen, directly in contact with the rising flames of the furnace andextending around the greater portion of its circumference. The invention1s equally applicable to both the stationarytype and tilting type'offurnace. Furthermore to further assure the cooling of the lining, amovable hollow ring kept entirely filled with water is provided. Therising gases are arranged topass out of the upper art of the foundationwhich receives the ower section of the rotary, furnace thus preventingtheflames Irom contacting with the lining of the the lower section ofthe furnace.

The open hearth furnace I use may constitute but a single chamber forreceiving the metal whether it be of the stationary type such as theMartin furnace or of the movable type such as the Wellmann furnace. Iprovide a dust chamber in communication with a rotary carburizingfurnace connected to a gas producing apparatus which burns all traces ofcombustible material.

My furnace is capable of producing pigiron or a less carbonized metalwithout silicon or sulfur, which metal is very liquid and becomes veryhot.

The annexed drawing taken with the specification, illustrates by way ofexample, an apparatus constructed after the principle of my invention.In" the drawing,

Fig. 1 is a view in elevation of the assembled apparatus, parts beingshown in section;

Fig. 2 is a plan view of the apparatus;

3 is a section along line 3-3 of Fig. 2;

Flg. 4 is a section along line 4-4 of Fig. 3; Fig.-5 is a section ofparts illustrated in F1g.'1 but drawn to a larger scale to more clearlyillustrate the invention, and

Fig. 6 is a detail of certain parts of the ap aratus.

eferring to the drawing, A represents a cylindrical rotary reducingfurnace, slightly inclined from the horizontal. This furnace may be ofany well known type of rotary furnace and is furnished with an interiorrefractory lining carried by the metallic casing of the furnace andextendin the full length of the furnace as is well own in the art.

Fixed to the, lower extremity of furnace A is a ring A of cast iron orsteel and which may be cylindrical but as here shown takes the form of atruncated cone. This ring is arranged to have water circulated through,it, cold water being admitted at the lowest portion and the hot waterbeing drawn off at the top.

Ring A (Fig. 6) is closed by means of a cover a in the form of anannulus, cut from sheet iron or steel and bearing against appropriate.annular flanges 0, ring A. Member at is held in place by means ofsprings d placed at intervals along its circumference. Said springs areprovided with rollers 2), which bear against a flange b fixed to thecasing of furnace A and rotatable therewith, at one end and bear againstcover a at the other end.

Ring A rojects into a metallic housing B which is iined with arefractory material. Within this lining are formed two vertical channelsf, f, symmetrically spaced with respect to the vertical axis of housingB and two horizontal channels connecting said vertical channels with theupper portion of housing B.

A masonry arch g of refractory material is provided on the interior ofmember B and serves as a protecting screen for the lower end of furnaceA. This arch may, if necessary, be cooled interiorly by a water jacket.

On the lower portion of housing B is formed a base which is cooled by awater spray, and opens into the smelting furnace C. The rotary furnace Ais laced into communication with furnace by means of the opening itpiercing the arch of the latter.

The smelting furnace C is of masonry and 0, carried by consists of asuitable refractory material held together by steel or iron plates. Theupper portion of the furnace takes the shape of an inverted truncatedcone and the lower portion that of a cylinder in which are lodged aplurality of interiorly cooled tuycrcs Said cylindrical portion is linedwith a refractory material and constitutes the crucible of the furnace.

On the periphery of the crucible near the lower part are disposed anumber of openings 0 which connect with the interiorof the furnace. Intoeach of these openings is inserted a carbon electrode a. The crucible isfurther provided with a tap p for drawing ofi the metal and a tap q fordrawing off the slag. The hearth of the furnace is of masonry and of arefractory material.

D is a rotary carburizing furnace comprising an inclined cylinderfurnished with a refractory lining similar to but shorter than furnaceThe extremities of the cylinder are provided with rings similar to ringA of furnace A. The extremities of furnace D are housed in casings F, Flined with a refractory material.

Housing F is furnished with an opening and a damper which connects witha pipe G leading to housing B. Housing F likewise is connected to anopen hearth furnace L by means of pipe K which communicates with openingt in said housing.

H represents any suitable gas producing apparatus which is provided witha pipe u for injecting air and steam.

The open hearth furnace L comprises a melting chamber, one end of whichconnects with a dust chamber M while the other end is closed by aremovable shield N which carries the cooled tuyeres a W is a tap fordrawing off the metal and Z is a funnel like spout through which thefurnace is charged with the molten metal from C.

A tuyere 7c is placed on housing F and a tuyere l is placed on housingB.

Helical screw conveyors m and a carry the materials to reducing furnaceA and the combustible to the carburizing furnace D respectively.

The upper extremity of reducing furnace A is provided with a dustchamber 0 in which any large dust particles carried along by the gascoming from A are caught. The gas is then led to gas washers throughpipe as in the usual manner. The lower portion of chamber 0 is closed bya water seal P.

The function of the apparatus is as follows:

Once the apparatus is started, ore mixed with the proper quantity ofcarbon is introduced into the rotary furnace A by means of conveyor m.The carbon may be in the form of lignite coal, peat, charcoal or wood. Asmall amount of flux is added, also through conveyor m. to give theproper consistency to the molten mass.

The materials introduced by the conveyor m become heated and the ore isreduced during their travel through furnace A. They attain. atemperature of from 1,000 to 1,100 degrees centigrade upon leavingfurnace A.

The molten mass then tumbles to the bottom of funnel-shaped casing B andthence into the reducing furnace C through opento add through opening yprovided in housing B for that purpose, a mixture of ore and limestonefor the purpose of. oxidizing the excess carbon as well as the siliciumcoming from the silica of the gangue which will be reduced by the carbonat the moment fusion of the mixture takes place.

The quantity of ore to be added may be determined from the results of ananalysis of a sample taken from the material issuing from furnace A. Theintroduction of the ore may be through the medium of an automaticapparatus if desired. The apparatus thus far described produces softsteel nearly free from silicium and of which the carbon content variesfrom 0.5% to 2%.

The metal on leaving furnace C may now be conveyed to open hearthfurnace L into which it is introduced through the opening Z, where afurther refining takes place and the necessary additions are made forobtaining the quality of steel desired. Through the charging doors offurnace L, scrap iron and other waste metal may be introduced as well asthe refining materials.

When the refining is completed, the metal is drawn off into ingot mouldswhich are placed in a pit B, through tap w.

A liquid, solid or gaseous combustible is mixed with hot air andintroduced into furnace L by means of tuyeres The mixture burns in themelting chamber of said furnace forming carbonic acid gas exclusivelyand gives to the fnrnace the necessary heat to accomplish the refiningoperation. The gases of combustion are led from the melting chamber intothe dust chamber and thence into pipe K where they enter the lowerextremit-y of furnace D through housing F In furnace D, the solidcombustible material is introduced in its upper end by means of conveyora. Under the influence of the heat content of the gases of combustionand their high temperature, the carbonic acid which they contain isreduced to carbonic oxide. The carbonic oxide and carbonic acidcontentis at least 9 parts by Weight when the gas leaves furnace D.

The tuyere situated on housing F is used to inject a mixture of a solid,liquid or gaseous combustible and hot air carrying sufficient heat toeffect the reduction of the carbonic acid thus maintaining thetemperature of the gases between 1250 and 1300 degrees centigrade at thepoint of leaving the furnace.

The gases leaving furnace D are conducted by the pipes G to housing Bwhere they enter at a temperature from 1150 to 1250 degrees centigrade.The gases here mix with those issuing from furnace C through channels f,pass into the furnace A and there supp y the necessaryamount of heat forproducing the required temperature to bring about the chemical actionsnecessary for reducing the mass of ore contained in furnace A.

The gases on leaving furnace A pass into the dust chamber 0 and fromthere are led to gas washers by means of pipe line a; and are finallyutilized in regenerators or other apparatus for the utilization of theirenergy content.

The combustible contained in furnace D burns when it contacts with thehot gases circulating therein. At the lower extremity of furnace D theresidues of combustion enter the housing F and pass into the gasproducer H by opening S where the residue of combustion accumulates.This residue which con sists of a mixture of cinders and coke issubjeeted to a current of air and steam issuing from pipe at. This airbecomes heated in contacting the incandescent mass and burns all tracesof coke. The cold cinders are drawn from the bottom of the apparatus I-Iwhenever necessary.

The tuyere Z situated on the front part of housing B may be used toinject either hot air or a mixture of hot air and a combustible forraising the temperature of furnace A at will.

The tuyeres z situated on the periphery of the cylindrical part offurnace C are employed at the time of starting the apparatus. Theyfurnish air to the combustible supplied to furnace C. During thefunctioning of the apparatus they-may be used to supply gas from chamberO to the unmelted mass coming from B. This gas contains a certain amountof carbonic acid which reduces the excess carbon content of the mass andat the same time raises its temperature and carries the surplus heat ofC to furnace A.

It is evident that many modifications might be made without departingfrom the scope of the invention as set forth in the appended claims. Forexample, open hearth furnace L might be replaced by an electric refiningfurnace. In this event furnace L could supply its gases directly byeliminating pipe K and utilizing tuyere It to supply continuously amixture of hot air and combustible material. The apparatus otherwisewould function as previously described.

The advantages derived from my invention may be summed up as follows:

The reduction to a minimum of the amount of solid combustible necessaryto mix with the ore and consequently a minimum of slag and sulphurpresent in the molten contents of the furnace.

The utilization of half burned cinders for heating purposes as well asthe burning of all sorts of combustible Waste material in thecarbureting furnace down to the last particle of combustible matter.

The employment of solid pulverized combustible materials in the openhearth fur nace.

The obtaining of cast iron or a less can bonized metal at will in thesmelting furnace, and

The utilization of the waste gases escaping from the open hearthfurnace.

Having described my invention, what I claim is:

1. In ore reducin apparatus, the combination of a smelting furnace, ahousing superimposed thereon, said housing being interiorly ofrefractory material with intercominunicating vertical and horizontalchannels within said refractory material a rotary reducing furnacehaving one of its ends opening into said housing and a refractory flamebafile within the housing adjacent said end of the rotary reducingfurnace.

2. In ore reducing apparatus, the combination of a smelting furnace, athollsing superimposed thereon, said housing being interiorly ofrefractory material, a rotary reducing furnace having one of its endsopening into said housing, a water cooled easing about the said end ofthe rotary reducing furnace, a refractory flame baflie within thehousing adjacent said end of the rotary reducing furnace, the refractorymaterial of the housing having interior intercommunicating channels toguide the gases arising from the smelting furnace out of the path ofmaterial issuing from the rotary reducing furnace.

Signed at Bilbao. Spain, in the Province of Viscaya and State of Spain,this llth day of April. A. D. 1927.

PIERRE JOSEPH PEYRACHON.

